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From: Bill Miller on 18 Jan 2010 11:41

"J Thomas" <jethomas5(a)gmail.com> wrote in message
news:q6T4n.8153$nR4.1335(a)newsfe01.iad...
Lots of <snips>
> Bill Miller wrote:
>
>>In contrast, there seems to be a fair amount of theoretical and lab
>> activity in taking carbonates (limestone, marble etc.) and subjecting
>> them to intense heat and pressure in the presence of water and Iron
>> oxide (as a catalyst). The outcomes contain all of the compunds usually
>> found in petroleum. Unfortunately, almost all this work is in Russian.
>> Here is a US site that links to many of the Russian works and also to an
>> impressive (to me) English language experiment re carbonates-to-oil.

Here is a better link to the experiment itself:

http://www.gasresources.net/AlkaneGenesis.htm

>>
>> http://www.gasresources.net/
>
> I'm not an expert in any of this. My own background leads me to think in
> terms of biological transformations that are hard to study in the lab.
>
> Any time there's an exothermic chemical reaction involving chemicals that
> could adsorb to a bacterial cell, there's the possibility that there are
> bacteria which use that reaction for their own energy. In practice the
> bacteria that use the reactions that release the most energy will tend to
> dominate, and if there are enough of them to support something that eats
> bacteria, then the slow-growing bacteria may get eaten faster than they
> can reproduce. So bacteria that slowly convert carbohydrates to
> hydrocarbons and water might survive well in lignite beds where they grow
> slowly but nothing else grows faster. And bacteria that slowly convert
> linear hydrocarbons to polycyclic hydrocarbons and methane might survive
> there. Etc. But it's hard to study such things in the lab, because if you
> study bacteria that have a doubling time of a few months then your grant
> is likely to run out before you get results.

Understood. *If* a biotic process exists and is s l o w enough, then not
only might the grant run out, but also the sands in the researcher's great
hourglass!

>
> So if you have organics trapped underground at a depth where bacteria can
> grow, it makes sense that they'd produce many of the things in petroleum,
> and those things would head upward if they could, and some of them would
> get trapped before they reached the surface. Methane that came from lower
> levels and also methane produced near the petroleum/water interface would
> tend to push petroleum out of the trap. Methane would also leave the trap
> both at the bottom and through whatever joints let it through.
>
> As a handwaving exercise it makes perfect sense that some of the oil
> would have a biological origin -- if there are biological materials that
> oil could be made from, oil will be made from them. Places that get too
> hot for bacteria might possibly create oil inorganically.
>
> Petrogeologists who find oil can usually point to a source strata that
> they think supplied biological carbon. That isn't proof, of course. Also
> they use that thinking when they look for oil so it's all biased samples.

Yeah. Kinda like the drunk that was looking for a dropped quarter under the
street light rather than in the dark alley where he dropped it. If, by
chance the quarter rolled out of the alley and under the light, then for the
rest of his life he'd look for quarters where the light was better.

>
> If you figure that the amount of methane etc that has been produced must
> have been far more than the amount that gets trapped, it would require a
> very different sort of seafloor in the old days. Much of the seafloor
> must have been anaerobic, and there would be a thick rain of dead stuff
> falling onto it. Modern oceans appear to produce less than a millimeter
> of sediment per thousand years. If that was the original source for the
> oil, we are no longer making very much of it.
>Presumably for some reason
> the oceans in those days were very productive while now they are
> comparatively dead.

I've seen some figures indicating that CO2 was at least 10X as plentiful
during the Triassic (3000 ppm) than today. That alone would seem to account
for a *much* more active accumulation of carbonate-bearing detritus than
what we see today. (Although if atmospheric CO2 continues to increase, then
we should expect to see an acceleration in aquatic detritus "fall" as more
available Carbon is trapped in shells and bones. )

BTW Saturn's moon, Titan seems to be "awash" with liquid hydrocarbons. It
stretches credibilty that this petrochemical accumulation might also be
biotic-caused.

>
> I looked over the link you provided. It sounds like the alternative idea
> is to create hydrocarbons using the earth's heat as an energy source.

Correct.

>The
> carbon would come from, say, CaCO3 while the hydrogen would come from
> H2O. I can imagine that this could happen, but to get one CH4 this way
> you would have 1 Ca and 7 O left over.

Please take a look at the link above. It shows what happens to the "extra"
Calcium and Oxygen that you have postulated.

>The oxygen would need to be
> sequestered somehow because if it left the mantle with the CH4 then the
> CH4 would be oxidised as soon as it reached bacteria that were ready for
> it -- which typically happens at the surface, where there is oxygen.

That's only correct is the process is as you suggest -- with extra bits left
over.

>
> Their argument is that oil must have been produced at high temperature
> and pressure, higher than the supposed biological sources could have,
> because that's the only way to create molecules bigger than ethane.

No. The arguent is that there is s dirth of eveidence that significant
amounts of big molecules *are* sourced biotically. And there is laboratory
evidence supporting the idea that abiotic petroleum *can* be made.

It also raises a question that is more philosophical than physical/chemical.
*If* big "organic-like" molecules *can* be made using an abiotic process,
then we would seem to have a ready source of life-precursor materials.

Significant amounts of hand waving are allowed and expected in any reply to
this!

..>But
> they are clearly wrong because bacteria easily produce molecules bigger
> than ethane at temperatures not much above the boiling point of water,
> and others consume them at room temperature when they have oxygen.
>
> I like their argument that most of the oil may have been produced this
> way. It does not require such a peculiar ocean in the pennsylvanian etc.
> But most of the abiogenic oil created over the last 200 million years
> would have escaped the various geological traps and been metabolised over
> the last 200 million years. Only the fraction that was trapped
> underground would be available now. Perhaps there are deeper traps than
> anyone has looked for? Maybe. Perhaps the existing oilfields and
> particularly methane fields might recharge faster than expected? That's
> nice but likely not enough to provide even enough fuel for another big
> war.
>
> <snip>>
> It would be interesting if the russian theories turned out correct. It
> might or might not have much practical significance.
>
> Sorry for all the handwaving. I don't have any definitive data.

That's OK. You are honest enough to say so.

Bill


From: Paul Hovnanian P.E. on 18 Jan 2010 13:01
J Thomas wrote:

[snip]

http://en.wikipedia.org/wiki/Abiogenic_petroleum_origin

> Russian petroleum geologists and US petroleum geologists have both been
> successful at finding oil. The americans sometimes factor in potential
> biological sources for oil when they are deciding where to drill. They
> figure that a dome that has no plausible biological source is a less
> likely choice than one which does have a source. If the russians don't
> figure that in, it would make some difference but maybe not a large
> difference.
>
> It would be interesting if the russian theories turned out correct. It
> might or might not have much practical significance.

And therein lies the economic basis for quite a bit of controversy. If there
are abiogenic sources for petroleum and one group or company gets the jump
on discovering these resources, big money is involved. It would behoove
them to deny the possibility of such resources ("Nothing to see here. Move
along now.") until such time as they can tie up the rights to such
resources.

--
Paul Hovnanian paul(a)hovnanian.com
----------------------------------------------------------------------
Have gnu, will travel.
From: Bernd Paysan on 19 Jan 2010 04:29
J Thomas wrote:
> The more CO2 in the oceans, the less of the carbonate reaches the bottom
> -- the small stuff gets dissolved as it sinks. A higher proportion of
> silica exoskeletons would reach the bottom, along with lots of organics.
> That might give us enough biological stuff to make oil from. Old oceans
> would be very different from today's oceans. For that matter, 10X CO2 in
> the air would not be very good for human beings. Let's hope that such
> times don't return before we go extinct.

Oh, you grossly underestimate the capabilities of human beings. 10x CO2
would be 0.3%, but CO2 becomes dangerous around 3 to 5%, and lethal between
8 and 10%. So we have a headroom of a factor 100 for CO2. There is some
reason for that - the air we exhale under normal condition contains ~4% CO2,
so that's why similar CO2 concentrations in the air start to become
uncomfortable - and even a fraction of those (e.g. 1%) can be noticed
through the increase of breathing frequency and/or volume.

Basic algorithm for idle breathing: Inhale (+500ml). Exhale (-500ml).
Stall until CO2 concentration > 4% (~50% of saturation level). Repeat. 50%
saturation level is an obvious point for optimal resource usage.

--
Bernd Paysan
"If you want it done right, you have to do it yourself"
http://www.jwdt.com/~paysan/
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